BackgroundDuring tumor formation and expansion, increasing glucose metabolism is necessary for unrestricted growth of tumor cells. Expression of key glycolytic enzyme alpha-enolase (ENO1) is controversial and its modulatory mechanisms are still unclear in non-small cell lung cancer (NSCLC).MethodsThe expression of ENO1 was examined in NSCLC and non-cancerous lung tissues, NSCLC cell lines, and immortalized human bronchial epithelial cell (HBE) by quantitative real-time reverse transcription PCR (qRT-PCR), immunohistochemistry, and Western blot, respectively. The effects and modulatory mechanisms of ENO1 on cell glycolysis, growth, migration, invasion, and in vivo tumorigenesis and metastasis in nude mice were also analyzed.ResultsENO1 expression was increased in NSCLC tissues in comparison to non-cancerous lung tissues. Similarly, NSCLC cell lines A549 and SPCA-1 also express higher ENO1 than HBE cell line in both mRNA and protein levels. Overexpressed ENO1 significantly elevated NSCLC cell glycolysis, proliferation, clone formation, migration, and invasion in vitro, as well as tumorigenesis and metastasis in vivo by regulating the expression of glycolysis, cell cycle, and epithelial-mesenchymal transition (EMT)-associated genes. Conversely, ENO1 knockdown reversed these effects. More importantly, our further study revealed that stably upregulated ENO1 activated FAK/PI3K/AKT and its downstream signals to regulate the glycolysis, cell cycle, and EMT-associated genes.ConclusionThis study showed that ENO1 is responsible for NSCLC proliferation and metastasis; thus, ENO1 might serve as a potential molecular therapeutic target for NSCLC treatment.Electronic supplementary materialThe online version of this article (doi:10.1186/s13045-015-0117-5) contains supplementary material, which is available to authorized users.

Promyelocytic leukemia zinc finger-retinoic acid receptor a (PLZF-RARa), a fusion receptor generated as a result of a variant t(11;17) chromosomal translocation that occurs in a small subset of acute promyelocytic leukemia (APL) patients, has been shown to display a dominantnegative effect against the wild-type RARa/retinoid X receptor a (RXRa). We now show that its N-terminal region ( (Fig. 1A): C.I, deletion of amino acids 172-348 containing 4 proline-dependent phosphorylation sites; C.II, deletion of amino acids 403-432 corresponding to the first zinc finger structure of PLZF; C.III, deletion of amino acids 432-455, thus lacking the second zinc

Recent studies demonstrate that UHRF1 is required for DNA methylation maintenance by targeting DNMT1 to DNA replication foci, presumably through its unique hemi-methylated DNA-binding activity and interaction with DNMT1. UHRF2, another member of the UHRF family proteins, is highly similar to UHRF1 in both sequence and structure, raising questions about its role in DNA methylation. In this study, we demonstrate that, like UHRF1, UHRF2 also binds preferentially to methylated histone H3 lysine 9 (H3K9) through its conserved tudor domain and hemi-methylated DNA through the SET and Ring associated domain. Like UHRF1, UHRF2 is enriched in pericentric heterochromatin. The heterochromatin localization depends to large extent on its methylated H3K9-binding activity and to less extent on its methylated DNA-binding activity. Coimmunoprecipitation experiments demonstrate that both UHRF1 and UHRF2 interact with DNMT1, DNMT3a, DNMT3b and G9a. Despite all these conserved functions, we find that UHRF2 is not able to rescue the DNA methylation defect in Uhrf1 null mouse embryonic stem cells. This can be attributed to the inability for UHRF2 to recruit DNMT1 to replication foci during S phase of the cell cycle. Indeed, we find that while UHRF1 interacts with DNMT1 in an S phase-dependent manner in cells, UHRF2 does not. Thus, our study demonstrates that UHRF2 and UHRF1 are not functionally redundant in DNA methylation maintenance and reveals the cell-cycle-dependent interaction between UHRF1 and DNMT1 as a key regulatory mechanism targeting DNMT1 for DNA methylation.

Bisphenol A (BPA) is widely used in plastic products, through which humans are exposed to it. Accumulating evidence suggests that BPA exposure is associated with b-cell dysfunction. Mitochondrial defects can cause impairment and failure of b cells, but there is little information about the effects of BPA on the mitochondrial function of b cells. In this study, we assessed the role of mitochondria-mediated mechanisms underlying BPA-induced b-cell dysfunction and resulting b-cell apoptosis. INS-1 cells were cultured with 0, 0.0020, 0.020, 0.20, or 2.0 lM BPA. Cell viability, glucose-stimulated insulin secretion (GSIS), and mitochondrial function were examined. The mitochondrial apoptotic pathway was also analyzed at molecular level. We found that BPA suppressed cell viability and disturbed GSIS in a dose-dependent manner. Positive Annexin-propidium iodide (PI) staining and altered expression of Bcl-2 family members and caspases in INS-1 cells indicated that the cells progressively became apoptotic after BPA exposure. Additionally, BPA-induced apoptosis was associated with mitochondrial defects in b cells, as evidenced by depletion of ATP, release of cytochrome c, loss of mitochondrial mass and membrane potential, and alterations in expression of genes involved in mitochondrial function and metabolism. Taken together, these findings provide strong evidence that BPA triggers INS-1 cells dysfunction and apoptosis may be meditated via the mitochondrial pathway.